Rechargeable batteries (e.g., lithium-ion batteries) generally include separators, which provide mechanical and electronic separation of the electrodes while allowing ionic conduction. One common separator is a porous polymer film that is soaked in a liquid electrolyte. However, the common liquid electrolytes for many batteries (e.g., Li-ion batteries) may be flammable and could contribute to a fire hazard in severe incidents. If an overcharge of a Li-ion battery occurs lithium dendrites may grow at the negative electrode and penetrate the porous membrane, leading to an internal short circuit. If the two electrodes make electrical contact, the cell can begin to self-discharge through the short, which may lead to a thermal-runaway event. Thermal-runaway may, in turn, lead to a fire hazard.